Self-retarding mechanical percussion fuse for projectiles



Jan. 16, A VARAUD SELF RETARDING MECHANICAL PERCUSSION FUSE FORPROJECTILES Filed Aug. 6, 1931 2 Sheets-Sheet l INVENTOR dmfc Vmuw( hwATTORNEY Jan. 16, 1934. A. VARAUD 1,943,706

SELF RETARDING MECHANICAL PERCUSSION FUSE FOR PROJECTILES BY ma NJM/Ahis ATTORNEY Patented Jan. 16, i934 SELF-RETARDING DECHANICAL PERCUS-SION FUSE F0 R PROJECTILES Andr Varaud, Geneva, Switzerland ApplicationAugust 6,

1931,- Serial No. 555,442,-

an-:l in Switzerland August 7, 1930' Y 6 Claims.

The object of the present invention is a selfretarding mechanicalpercussion fuse, for projectiles, characterized by mechanical meanswhich, at the moment of impact, prevent ignition of the charge by pointof the striker at least until the moment when an important part of themomentum of the projectile has been absorbed by the obstacle.

The annexed drawings show, only by way of example, two forms ofexecution of the object of the invention, applied to a perforating shellof small bore.

Fig. 1 shows the fuse and the shell according to the first form ofexecution in axial section in a transportable condition.

Fig. 2 is an axial section ofthe shell with its pyrotechnical equipmentand shows the position taken up by the organs of the device at themoment of impact.

Fig. 3 is also an axial section of the shell, at the moment of functionof the percussion, after the projectile has overcome the resistance ofthe obstacle or that its momentum is almost entirely absorbed.

Fig. 4 is a cross section made according to the une A-A of Fig. 1,

Fig. 5 is a View in detail in elevation of the striker of the fuse and,

Fig. 6 is an elevation of the organ of command of the percussion.

Fig. '7 is an axial section of the fuse according to the second form ofexecution with its pyrotechnical equipment and shows the position of thevarious organs in a transportable condition.

Fig. 8 is also an axial section of the fuse as shown in Fig. 7, but atthe moment of impact (beginning of the movement).

Fig. 9 is an axial section of the fuse showing the position of thevarious organs at the moment of impact (termination of the movement).

Fig. 10 is an axial section of the fuse, at the moment of function ofthe percussion, after the projectile has overcome the resistance of theobstacle or that its momentum is almost entirely absorbed.

In referring to the drawings, it is seen that the fuse according to therst form of execution comprises: the bottom plug 1 on which is screwed abody 2 which carries a socket at its front extremity, screwed on to thebody and containing the primary detonator. The body 2 is piercedlongitudinally by two cylindrical bores, which lie parallel to the axisof the projectile and at an equal distance from this axis. In one ofthese bores a striker 4, toothed in the manner of a rack (o1. 1oz-39)4a, can slide freely and in the other a cylinder 5 also toothed in thesame manner.

This striker 4 and this cylinder 5 are joined together in theirmovements by a pinion 6, radially situated between them, whichcooperates with their respective teeth.

A Screwed plug 6a maintains this pinion in its place.

The striker 4 acts under the influence of a helicoidal spring 4b whichtends to push the latter towards the percussion cap 8.

A centrifugal bolt 9, perforated by a bore 9a in which is engaged aprojection 5b of the cylinder 5, assures that this latter is in atransportable condition, that is to say, in the position where thestriker 4 is maintained away from the percussion cap 8.

As will be seen in Fig. 1, the spring 4b, which is only partlystretched, pushes the striker 4 in the direction of the percussion cap,but as the teeth 4a are engaged with the pinion 6, this latter tends toturn counter-clockwise, as indicated by the arrow (Fig. 1) and 'tends tocause the cylinder 5 to descend.

But because the centrifugal bolt 9 engages under the cylinder and isfurther maintained in its active position by the introduction of theprojection 5b into the bore 9a, the cylinder cannot effect thisdescending movement, in such a way that the striker 4 is maintained awayfrom the percussion cap. Y

The function'of the fuse is the following:

At the departure of the charge and underv the action of centrifugalforce, the organs of the fuse do not leave the position they occupy inFig. 1, either during the lineal acceleration or during the ilight.

In fact, during the lineal acceleration, the cylinder 5, which is muchheavier than the hollow striker 4, remains appliedby inertia to thecentrifugal bolt 9, and during the flight, this bolt is maintained inits active position against the action of the centrifugal force, by theprojection 5b of the cylinder 5.

At the moment of impact, the cylinder 5 comes, by inertia, into theposition represented in Fig. 2, and by means of its teeth draws thepinion 6 in the clockwise direction; this latter simultaneouslycommunicates its movement to the striker 4, by the intermediary of thestrikers teeth 4a,4 which compresses the spring 4b in causing thestriker to retreat from the percussion cap.

When the projectile has overcome the resistance of'the obstacle, thickiron plating, wall, concrete work etc., and that the momentum of 110 thecylinder 5 is absorbed, the spring 4b acts and pushes the striker in thedirection of the percussion cap, in causing the pinion 6 to turncounterclockwise.

But as the centrifugal bolt 9 has been freed, by the forwarddisplacement of the cylinder 5, at the moment ofimpact, the centrifugalforce brings the bolt 9 into the position represented in Fig. 3 whichcauses the cylinder 5 to be displaced suiciently backwards by the pinion6 so that the teeth 4a of the striker escapes the teeth of the pinion 6.

In fact, towards the opposite extremity of the point 4d of the striker,a fla-t cut part 4c is provided (Fig. 5) in order that the last tooth ofsaid striker may suddenly escape the teeth of the pinion 6, and thuscause the percussion spring 4b to stretch and cause the deagration ofthe percussion cap 8 and at the same time the explosion of theprojectile.

The fuse according to the second form of execution also comprises abottom plug 10 which alone has been represented in Figures 7 to 10. Thisplug is partly grooved, this grooving comprising two cylindrical bores,which lie parallel to the a-,XiS of the projectile and at an equaldistance from the axis. These two bores are closed by a socket 11screwed in the plug, and containing the primary detonator.

In one of these two bores may slide a striker 12 formed by a shortcylinder rendered lighter by a circular neck andY carrying, on the onehand, the point of the striker, and on the other hand, an abutment 13.

In the other bore a cylinder 14 may slide having three notches of whichone, 15, relatively short is separated from another, 16, relativelylong, by a tooth 17, the third notch 18 taking the form of thecentrifugal bolt 19 penetrating into this third notch.

The striker 12 and this cylinder 14 are dependent upon each other intheir movement by an oscillating organ 20 in the form of a lever ofwhich one arm is able to penetrate into one or the other of the notches15 and 16 and the other arm of which, in the form of a beak, is able toretain the striker 12 away from the percussion cap 21. This oscillatingorgan 20 turns about a pivot situated in the axis of the fuse anddirected according to a diameter of this latter perpendicular to theplane passing through the axis of the two bores.

rIhe striker 12 is under the action of a helicoidal spring 22 whichtends to push this latter towards the percussion cap 21. A rod 23 isplaced concentrically to this spring and is intended, at a given moment,to be met by the abutment 13 of the striker 12.

In the position represented in Fig. 7 the spring 22 is sufficiently tautto be able to cause the displacement of the striker l2 in the directionof the percussion cap 2 1, but this displacement is rendered impossibledue to the fact that, on the one hand, the beak of the oscillating organ20 stops the striker and that, o n the other hand, this organ cannotturn, given that it penetrates into the notch 15 of the cylinder 14 andcomes to bear upon the tooth 17 of this cylinder. The cylinder, on theother hand, cannot be displaced because it is maintained in place by thecentrifugal bolt 19.

The function of this second form of execution of the fuse is as follows:

At the departure of the charge, the organs of the fuse do not leave theposition which they occupy in Fig. 7, nor during the linealacceleration, nor during the flight, with the exception of the bolt 19which, under the influence of the centrifugal force, liberates thecylinder 14.

In fact, during the lineal acceleration the cylinder 14 remains appliedby inertia against the bottom of its lodgement. During the flight, thecylinder 14 continues to be maintained in this position by the pressureof the oscillating organ 20 on the tooth 17 caused by the spring 22.

VAt the moment of impact, the cylinder 14, by inertia, takes up theposition represented in Fig. 8,. So doing, it causes, by theintermediary of the tooth 17, an oscillation of the organ 20 in theclockwise direction and by reason of this, a compression of the spring22 by momentarily drawing the striker 12 away from the percussion cap21. The striker abuts against the rod 23 of which the length must besuch that the oscillating organ 20 may be moved out of the path of thetooth 17, but not accomplish a rotation such that the pressure of thestriker on the organ 20, no longer acting upon the beak, causes ablockage of the whole device. In fact,k and as shown in Fig. 9,immediately the tooth 17 has passed in front oi the oscillating organ20, this latter must be caused to turn in the counter-clockwisedirection and this under the influence of the pressure of the striker onthe beak, and until this movement be in its turn stopped by theengagement of the organ 2G in the notch 16 of the cylinder 1 4.

The length of this notch must be such that it stops the oscillation ofthe organ 20 in a position where the beak of this latter still retainsthe striker l2 which will, however, be brought nearer to the percussioncap 21.

When the projectile has overcome the resistance of the obstacle and themomentum of the cylinder 14 is absorbed, the spring 22 pushes thestriker in the direction of the percussion cap, forcing the beak of theorgan 20 to be moved aside, this organ oscillating to this eifect in thecounter-clockwise direction, which is rendered possible by a slightrecoil of the cylinder 14.

The striker is liberated and penetrates into the percussion cap andproduces the Vdeflagration of same, the organs of the f use then occupythe position represented in Fig. 10.

Instead of being applied to a bottom fuse the device according to theinvention may be applied to a head fuse, for all kinds of artilleryprojectiles or others, aeroplane bombs, etc. without the scope of theinvention being limited in any way.

What I claim as my invention and desire to secure by Letters Patent ofthe United States of America is:

1. A self-retarding mechanical percussion fuse for projectiles,comprising a body'pierced by two cylindrical bores which lie parallel tothe axis of the fuse and situated at an equal distance from Said axis, astriker freely slidable in one of the bores and a cylindrical mass inthe other, the striker and mass being toothed inthe manner of a rack, apinion connecting these last` namedv the same, and a. centrifugal boltassociated with the icylindrical mass by which the same is retained inposition until moved due to its inertia at the moment of impact of theprojectile.

3. A self-retarding mechanical percussion fuse for projectiles,comprising a body member, a toothed striker and toothed cylindrical massfreely slidable in separate bores provided for the same in the body, thebores being arranged parallel to the axis of the projectile, a pinionconnecting the striker and mass at the toothed portions of the same, apercussion cap, a percussion spring associated with the striker, acentrifugal bolt associated with the cylindrical mass by which the sameis retained in position until moved due to its inertia at the moment ofimpact of the projectile, the mass at such time urging the strikerthrough the medium of the pinion to compress the percussion spring, thestriker then being urged against the percussion cap by the expansion ofthe percussion spring.

4. A self-retarding mechanical percussion fuse for projectiles,comprising a body pierced by two cylindrical bores which lie parallel tothe axis of the fuse and situated at an equal distance from this axis, astriker freely slidable in one of the bores and a cylindrical mass inthe other, an oscillating lever engaging, on the one hand, a. notch inthe cylindrical mass and retaining, on the other hand, by means of abeak, the striker element, a percussion spring associated with thestriker to maintain the same in a position against the beak of thelever, and a centrifugal bolt for normally retaining the cylindricalmass irnmovable.

5. A self-retarding mechanical percussion fuse for projectiles,comprising a striker and a cylindrical mass each sliding freely in oneof two cylindrical bores, which lie parallel to the axis of theprojectile, a percussion spring for urging the striker to a ringposition, an oscillating lever engaging in a notch of the mass, andretaining the striker by means of a beak against the action of thespring, a centrifugal bolt for normally retaining the cylindrical massimmovable, the mass having a second notch, which the oscillating leverengages after the same has moved forward due to its inertia at themoment of impact of the projectile, to thereby facilitate the movementof the lever so that its beak leaves the striker.

6. A self-retarding mechanical percussion fuse for projectiles,comprising a striker and a cylindrical mass each sliding freely in oneof two cylindrical bores which lie parallel to the axis of theprojectile, said cylindrical mass having two notches thereon, apercussion spring for urging the striker to a ring position, anoscillating lever engaging, on the one hand, a notch of the cylindricalmass, and on the other, retaining by means of a beak the striker againstthe action of the percussion spring, a percussion cap, an abutmentlimiting the recoil of the striker away from the percussion cap when aforward movement of the cylindrical mass at the moment of impact, causesthe said striker to compress the percussion spring by the intermediaryof the beak of the oscillating lever, when the oscillating organdisengages with the notch of the cylindrical mass to engage in thesecond notch of said mass.

ANDR VARAUD.

